package model;

import com.mysql.jdbc.Connection;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

/**
 * \* Created with IntelliJ IDEA.
 * \* model.User: Administrator
 * \* Date: 2022/6/8
 * \* Time: 19:38
 * \* To change this template use File | Settings | File Templates.
 * \* Description:
 * \
 */
public class BlogDao {
    //1.往博客表中插入博客
    public void insert(Blog blog){
        //JDBC基本代码
        Connection connection = null;
        PreparedStatement statement = null;
        try {
            //1.和数据库建立连接
            connection = DBUtil.getConnection();

            //2.构造sql语句
            String sql = "insert into blog value(null,?,?,?,now())";
            statement = connection.prepareStatement(sql);
            statement.setString(1,blog.getTitle());
            statement.setString(2, blog.getContent());
            statement.setInt(3,blog.getUserId());

            //3.执行sql
            statement.executeUpdate();

        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }finally {
            //4.关闭连接，释放资源
            DBUtil.close(connection,statement,null);
        }

    }
    //2.能够获取到博客中的所有博客的信息（用于博客列表页）
    public List<Blog> selectAll(){
        List<Blog>blogs = new ArrayList<>();
        Connection connection = null;
        PreparedStatement statement = null;
        ResultSet resultSet = null;
        try {
            connection = DBUtil.getConnection();
            String sql = "select * from blog order by postTime desc";
            statement = connection.prepareStatement(sql);
            resultSet = statement.executeQuery();
            while (resultSet.next()){
                Blog blog = new Blog();
                blog.setBlogId(resultSet.getInt("blogId"));
                blog.setTitle(resultSet.getString("title"));

                String content = resultSet.getString("content");
                if(content.length() > 50){
                    content = content.substring(0,50) + "...";
                }
                blog.setContent(resultSet.getString("content"));
                blog.setUserId(resultSet.getShort("userId"));
                blog.setPostTime(resultSet.getTimestamp("postTime"));
                blogs.add(blog);
            }

        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }finally {
            DBUtil.close(connection,statement,resultSet);
        }
        return blogs;
    }
    //3.能够根据博客id获取到指定的博客内容（用于博客详情页）
    public Blog selectOne(int blogId){
        Connection connection = null;
        PreparedStatement statement = null;
        ResultSet resultSet = null;
        try{
            connection = DBUtil.getConnection();
            String sql = "select * from blog where blogId = ?";
            statement = connection.prepareStatement(sql);
            statement.setInt(1,blogId);
            resultSet = statement.executeQuery();
            if (resultSet.next()) {
                Blog blog = new Blog();
                blog.setBlogId(resultSet.getInt("blogId"));
                blog.setTitle(resultSet.getString("title"));
                blog.setContent(resultSet.getString("content"));
                blog.setUserId(resultSet.getShort("userId"));
                blog.setPostTime(resultSet.getTimestamp("postTime"));
                return blog;

            }
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }finally {
            DBUtil.close(connection,statement,resultSet);
        }
        return null;
    }

    //4.从博客列表中，根据博客id删除博客
    public void delete(int blogId){
        Connection connection = null;
        PreparedStatement statement = null;

        try{
            connection = DBUtil.getConnection();
            String sql = "delete from blog where blogId = ?";
            statement = connection.prepareStatement(sql);
            statement.setInt(1,blogId);
            statement.executeUpdate();
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }finally {
            DBUtil.close(connection,statement,null);
        }
    }
}
